90 Mr. Faraday on the [Feb. 



faint yellow colour, having very much the appearance of water ; 

 the remaining fourth was a heavy bright yellow fluid, lying at 

 the bottom of the former, without any apparent tendency to mix 

 with it. As the tube cooled, the yellow atmosphere condensed 

 into more of the yellow fluid, which floated in a film on the pale 

 fluid, looking very like chloride of nitrogen ; and at 70° the pale 

 portion congealed, although even at 32° the yellow portion did 

 not solidify. Heated up to 100° the yellow fluid appeared to 

 boil, and again produced the bright coloured atmosphere. 



By putting the hydrate into a bent tube, afterwards hermeti- 

 cally sealed, I found it easy, after decomposing it by a heat of 

 100°, to distil the yellow fluid to one end of the tube, and so 

 separate it from the remaining portion. In this way a more 

 complete decomposition of the hydrate was effected, and when 

 the whole was allowed to cool, neither of the fluids solidified at 

 temperatures above 34°, and the yellow portion not even at 0°. 

 When the two were mixed together, they gradually combined at 

 temperatures below 60°, and formed the same solid substances 

 as that first introduced. If, when the fluids were separated, the 

 tube was cut in the middle, the parts flew asunder as if with an 

 explosion, the whole of the yellow portion disappeared, and 

 there was a powerful atmosphere of chlorine produced ; the pale 

 portion on the contrary remained, and when examined, proved 

 to be a weak solution of chlorine in water, with a little muriatic 

 acid, probably from the impurity of the hydrate used. When 

 that end of the tube in which the yellow fluid lay was broken 

 under a jar of water, there was an immediate production of 

 chlorine gas. 



I at first thought that muriatic acid and euchlorine had been 

 formed ; then, that two new hydrates of chlorine had been pro- 

 duced ; but at last I suspected that the chlorine had been 

 entirely separated from the water by the heat, and condensed 

 into a dry fluid by the mere pressure of its own abundant vapour. 

 If that were true, it followed, that chlorine gas, when com- 

 pressed, should be condensed into the same fluid, and, as the 

 atmosphere in the tube in which the fluid lay was not very yel- 

 low at 50° or 60°, it seemed probable that the pressure required 

 was not beyond what could readily be obtained by a condensing 

 syringe. A long tube was therefore furnished with a cap and 

 stop-cock, then exhausted of air and filled with chlorine, and 

 being held vertically with the syringe upwards, air was forced 

 in, which thrust the chlorine to the bottom of the tube, and gave 

 a pressure of about four atmospheres. Being now cooled, there 

 was an immediate deposit in films, which appeared to be hydrate, 

 formed by water contained in the gas and vessels, but some of 

 the yellow fluid was also produced. As this however might 

 also contain a portion of the water present, a perfectly dry tube 

 and apparatus were taken, and the chlorine left for some time 



